Hi Mike and family. Do you know what style you want? This will largely influence your direction and my advice. Take the free quiz here and let me know. https://www.dsasociety.org/resources/interior-design-style-quiz/

Really though, the floor is gorgeous. My decision would be heavily influenced by what you plan to do for other fixtures/ vanity. Are those decided?

That's a good point, Lauren, and the floor IS gorgeous. I just saw a bathroom with the same style floor ( couldn't grab photo) where they used a black vanity and had black framed mirrors above it. Here you could paint the window black.

Could you do the rest of the wall in white square tile with maybe a stripe to mimic the floor -- something along these lines?

I'm starting to wonder if the black is going to throw the room off balance? Maybe the white should carry over under the window to the corner and just use the black tile on one wall for an accent wall.

I'd be taping up black garbage bags on that wall, for sure, lol.

^^thats what I was thinking. Like a black bullnose edge atop white tiles.

Great suggestions, thanks. Thank you also for liking my floor. It was a real learning experience laying it all out. Barncatz, I agree and was going to remove the bullnose tiles which will pretty much bring the edge to window edge. Lauren, I fell in love with console sinks while looking at different styles. I like the openness underneath. I'm leaning toward a medicine cabinet like the one pictured and probably one of the two sinks pictured. I like the more angular one and my wife prefers the more curved shape. Love the idea of the white tiles with a black border or design to mirror the floor. I will discuss with SHMBO.

It's a beautiful floor. I wouldn't muddle up the style with a third tile next to the shower tile. I think your first idea of wainscoting is best. If you want those open sinks, you could do black wainscoting and white paint above, with a textured white shower curtain. Or white wainscoting with a dramatic dark wall paint. Have you thought above where to store towels, extra toilet paper, etc. if you use those open sinks rather than a vanity?

this would work.

or these

Calidesign, food for thought, thanks. Not shown in the picture to the left is a 4 foot long wall that backs up to a closet in the adjoining bedroom. I will put storage in that wall either open or with doors. Beth H., thanks for the pictures. The floor in the first picture was what I was going to do with the floor originally before opting out. And even as I was installing the tiles I was regretting not doing a green and black combination as in the House Beautiful picture.

Your floor is wonderful.